GB2580487A

GB2580487A - Vibration system of a loudspeaker

Info

Publication number: GB2580487A
Application number: GB1915811.2A
Authority: GB
Inventors: Chen Zhiwen
Original assignee: Tymphany Acoustic Technology Huizhou Co Ltd
Current assignee: Tymphany Acoustic Technology Huizhou Co Ltd
Priority date: 2018-12-07
Filing date: 2019-10-31
Publication date: 2020-07-22
Also published as: DE102019129402A1; US20200186914A1; US11463802B2; GB201915811D0; CN209314064U

Abstract

The vibration system is suitable for an ultra-thin full-range loudspeaker. Frameless winding voice coils 2 are directly adhered on diaphragm 1. Each coil is a planar coil formed by winding a single enamelled wire. Each planar coil may be of a racetrack shape or an annular shape, and the enamelled wires are arranged by tightly contacting to each other. The coils are directly adhered on the diaphragm, and lead wires of the voice coils are tightly arranged. Two or more coils may be used simultaneously and connected to each other in a series electrical connection or parallel electrical connection

Description

VIBRATION SYSTEM OF A LOUDSPEAKER

Technical Field

The present invention relates to the technical field of manufacturing a loudspeaker, and in particular to a vibration system of a loudspeaker.

Background

At present, various electronic products, such as an ultra-thin television and a portable sound box, have placed increasing demand on reducing the thickness of such devices. In turn, the product structure of a loudspeaker, in particular a so-called high-performance ultra-thin full-range loudspeaker, having a smaller thickness is also required.

For the existing full-range loudspeaker, which is a single loudspeaker unit capable of producing sound output across the whole range which is audible to the human ear (at best 12Hz to 28kHz, but usually from around 20Hz to 20KHz), a vibration system includes a diaphragm and flexible voice coils prepared with a printing-etching process. The printed voice coils have the advantage of allowing great freedom when wiring the lead wires to form the routing layout with various complex shapes. However, the voice coils also have the following defects: (1) the printed voice coils must take a flexible insulating planar thin film as a base material and the base material is used as a carrier for printing the voice coils and also forms one part of the vibration system of the loudspeaker, so as to increase inevitably the thickness and the vibration mass, and to reduce an output sensitivity; and (2) while wiring the printed voice coils, a certain space between the lead wires is necessary to prevent any short circuits, and a thickness of each lead wire is usually very small and there are only very few common specifications of the lead wires provided, so that a thickness adjustment of each lead wire is greatly limited. That is, the cross section of a single lead wire for allowing a current passing through is limited, which determines that the flexible printed voice coils cannot carry a very high input power.

Therefore, it is necessary to optimize the vibration system of the above-mentioned full-range loudspeaker to improve the output sensitivity of the full-range loudspeaker

Summary

In order to solve the above-mentioned problems of the prior art, the present invention provides a vibration system of an ultra-thin full-range loudspeaker According to the vibration system, frameless winding voice coils are directly adhered on a diaphragm, and lead wires of the voice coils are arranged tightly to each other, so that a space utilization rate in a magnetic gap is effectively improved, and a driving force factor BL and an output sensitivity are improved.

To achieve aforesaid purposes, the present invention provides the following technical solution: A vibration system of an ultra-thin full-range loudspeaker includes a diaphragm and frameless winding voice coils directly adhered on the diaphragm, where each frameless winding voice coil is a planar coil formed by winding a single enamelled wire, and the enamelled wires are arranged by tightly contacting to each other.

Each frameless winding voice coil is formed by winding the single enamelled wire. As surfaces of the enamelled lead wires are insulated, the enamelled wires can be arranged by tightly contacting to each other. In this way, a space utilization rate in a magnetic gap is improved to a great extent so as to improve the driving force factor BL (magnetic coefficient) of the loudspeaker. Additionally, since such winding voice coils do not require a bobbin, and a plane of each winding voice coil can be directly adhered on the diaphragm, so that the unnecessary weight can be reduced. The ultra-thin property of the full-range loudspeaker is further ensured, and also an output sensitivity of the loudspeaker is improved.

As a further description for the technical solution of this invention, each planar coil is in a shape of a racetrack or an annularity, or other shapes as required by the design.

As a further description for the technical solution of this invention, when two or more frameless winding voice coils are used simultaneously, the frameless winding voice coils are connected in a series connection or parallel connection manner. The two or more frameless winding voice coils are connected in the series connection or parallel connection manner, and are also adhered on the diaphragm to drive the diaphragm vibrating and generating sounds, so that the mechanical stroke is ensured.

As a further description for the technical solution of this invention, when two or more frameless winding voice coils are used simultaneously, the frameless winding voice coils are placed horizontally in parallel, or placed by overlapping up and down, or arranged in any other manner as required by the design.

As a further description for the technical solution of this invention, the enamelled wire of each frameless winding voice coil has a thickness and a wideness in a range of 0.05 mm to 0.5 mm. As a further description for the technical solution of this invention, the enamelled wire of each frameless winding voice coil is a flat wire or a rounded wire.

As a further description for the technical solution of this invention, each enamelled wire is a copper wire, an aluminium wire or a copper-clad aluminium wire.

In the vibration system provided by the present invention, the enamelled lead wires of the frameless winding voice coils are the flat wires each having a thickness of 0.4 mm thick and a wideness of 0.2 mm, the enamelled lead wires are arranged closely, and a plurality turns of lead wires (e.g., eighteen turns of lead wires) can be arranged in one single magnetic gap, so that the magnetic energy in the magnetic gap can be more sufficiently utilized. The vibration system may further use voice coil wires of other specifications. In this way, the bearing power is not limited by a carrying current of a cross section of lead wires such as flexible printed voice coils. The present invention further provides an ultra-thin planar magnetic diaphragm full-range loudspeaker including the above-mentioned vibration system. Compared the ultra-thin planar magnetic diaphragm full-range loudspeaker with the conventional moving coil type loudspeaker, it has better power tolerance and better heat dissipation property of the planar structure.

Based on aforesaid technical solutions, the invention achieves the following technical effects: (1) According to the vibration system of the ultra-thin full-range loudspeaker provided by the invention, the frameless winding voice coils are directly adhered on the diaphragm, and the enamelled wires are arranged by tightly contacting to each other, that a space utilization rate in the magnetic gap is effectively improved, so as to improve the driving force factor.

(2) According to the vibration system of the ultra-thin full-range loudspeaker provided by the invention, the winding voice coils do not require a bobbin, and a plane of each winding voice coil can be directly adhered on the diaphragm, so that the unnecessary weight is reduced, the ultra-thin property of the full-range loudspeaker is further ensure, and the output sensitivity of the loudspeaker is improved.

(3) The ultra-thin planar magnetic diaphragm full-range loudspeaker including the above-mentioned vibration system has uniform stress applied on the diaphragm, good power tolerance, heat dissipation property, and can be widely utilized on a thin electronic device.

Brief Description of the Drawings

FIG. 1 is an exploded diagram of a vibration system of a loudspeaker according to the present invention.

FIGS 2A and 2B are connection schematic diagrams of a frameless winding voice coil according to the present invention FIG. 3 is an arrangement schematic diagram of an enamelled wire of a frameless winding voice coil according to the present invention.

FIG. 4 is a structural schematic diagram of an enamelled wire of a frameless winding voice coil according to the present invention FIG. 5 is a structural schematic diagram of a flexible printed voice coil and a substrate.

FIG. 6 is a Sound Pressure Level (SPL) frequency response curve diagram of a loudspeaker using a frameless winding voice coil and a loudspeaker using a flexible printed voice coil.

Detailed Description of the Embodiments

In order to understand the present invention conveniently, this invention will be described more thoroughly in conjunction with the accompanying drawings and specific embodiments. Preferred implementation of this invention are given in the accompanying drawings. However, this invention may be implemented in many different forms and is not limited to the implementation described herein. Conversely, the purpose of providing these implementation concepts is to understand the contents of the invention more thoroughly and comprehensively. It is to be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or an intervening element may also be present. When one element is considered as being "connected to" the other element, it may be directly connected to the other element or an intervening element may also be present.

For the ease of reading, the "upper", "lower", "left" and "right" indicated according to the accompanying drawings are merely for indicating a relative reference position of each element and are not intended to limit the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art to which the invention belongs. Terms used herein in the specification of the invention are merely for describing the specific implementation but are not intended to limit the invention; the invention is described by the claims.

Embodiment 1 FIG. 1 is a structural exploded diagram of a vibration system of a loudspeaker in this embodiment. As shown in FIG. 1, the vibration system 100 of the loudspeaker includes a diaphragm 1 and frameless winding voice coils 2, wherein the frameless winding voice coils 2 can be directly adhered to the diaphragm 1 without preforming a connection through a substrate during the attachment process. The process of adhering the frameless winding voice coils 2 to the diaphragm can proceed by any method, in particular by one or more of glue, UV glue, tape, double-sided tape, laser welding, or injection moulding, without limitation. It is to be noted that each frameless winding voice coil is formed by winding a single enamelled wire and has a racetrack-shaped planar coil structure in this embodiment. Certainly, each frameless winding voice coil may also be in an annular shape or other shapes according to design requirements and the form shown in the figures is not limiting.

In the frameless winding voice coils, since surfaces of the enamelled (lead) wires are insulated, the enamelled wires can be arranged so that they are in contact with each other. In this way, the space utilization rate in a magnetic gap is improved greatly, and the driving force factor BL (magnetic coefficient) of the loudspeaker is improved.

FIGS. 2A and 2B details a connection schematic diagram of a frameless winding voice coil in this embodiment. As shown in FIGS. 2A and 2B, in this embodiment, the vibration system uses two frameless winding voice coils, wherein the frameless winding voice coils can be connected in a series connection manner marked as 2A, and can also be connected in a parallel connection manner marked as 2B. Certainly, when multiple frameless winding voice coils are connected, the series connection or parallel connection can also be used. The frameless winding voice coils connected together in the series connection or parallel connection manner are adhered on the diaphragm, so as, in unison, to drive the diaphragm into vibrating and to generate sounds, so that the mechanical stroke of the loudspeaker is ensured.

It is further to be noted that when two or more frameless winding voice coils are used simultaneously, the frameless winding voice coils can be arranged horizontally in parallel, or arranged by overlapping in the vertical direction, or arranged in any other manner according to final design requirements.

FIG. 3 and FIG. 4 are an arrangement schematic diagram and a structural schematic diagram of an enamelled wire of a frameless winding voice coil in this embodiment. Referring to FIG. 3 and FIG. 4, the enamelled wire 21 of each frameless winding voice coil can use a flat enamelled wire, a square enamelled wire, a rectangular cross-section enamelled wire or a round enamelled wire, and can be made of a copper wire, an aluminium wire or a copper-clad aluminium wire; any other appropriate wire material may also be considered, as required. It is to be noted that the enamelled wires of the frameless winding voice coils are arranged by positioning the adjacent wires in contact tightly with each other, whatever shapes or materials of the enamelled wires are adopted. That is, in the vibration system provided by this embodiment, there are various specifications of the voice coils enamelled wires which can be selected -in particular, larger cross-section wires than can be used in the printing-etching process of the prior art. In this way, the carrying power is not limited by a carrying current of a cross section of lead wires such as in the flexible printed voice coils of the prior art.

In this embodiment, pure aluminium flat enamelled wires are preferably selected for winding. As shown in FIG. 3, an arrangement of the flat enamelled wires is more close-packed than that of the round enamelled wires and has a lower duty ratio, so that a maximum utilization rate of a magnetic gap space can be achieved. Moreover, the aluminium voice coils have a lighter weight thereby effectively reducing the mass of the voice coils and increasing output sensitivity For the sake of comparison, FIG. 5 is a structural schematic diagram of a flexible printed voice coil and a substrate of the prior art technique. As shown in FIG. 5, the flexible printed voice coils 3 are required to be adhered over the substrate 4 first and then adhered on a diaphragm as a whole. In the flexible printed voice coils shown in FIG. 5, each lead wire has a thickness of 35tim and a width of 0.5mm, and a distance between the lead wires is 0.1mm. In this way, only six turns of lead wires can be applied into a single magnetic gap, so that a sensitivity test result of a loudspeaker sample using the flexible printed voice coils is 79 dB (1m/1W). The reason for this lower sensitivity is that the printed voice coils must take a flexible insulating flat diaphragm as a base material. The base material also forms a part of the vibration system of the loudspeaker as a carrier of the printed voice coils, and thus a vibrating mess is inevitably increased and an output sensitivity is therefore reduced.

Referring to FIG. 4 again, which shows a structural schematic diagram of an enamelled wire of a frameless winding voice coil, the lead wire of each voice coil is a flat wire having a thickness and width in a range from 0.05mm to 0.5mm. An embodiment of the flat wire of each voice coil has a thickness of 0.4mm and a width of 0.2mm. The lead wires are arranged closely, ideally each lead wire is arranged in contact with the adjacent lead wire. There is a plurality of turns of the lead wires (e.g., eighteen turns of lead wires) which can be arranged into a single magnetic gap, so that the magnetic energy in the magnetic gap can be sufficiently utilized. A sensitivity test result of a loudspeaker sample using such frameless winding voice coils is 84 dB (1m/1W). In a comparative loudspeaker test with the same magnetic circuit design, the driving force factor BL of the loudspeaker using the frameless winding voice coils is three times the driving force factor BL of the loudspeaker using the flexible printed voice coils.

FIG. 6 is an SPL frequency response curve diagram of a loudspeaker using the frameless winding voice coils and a comparative loudspeaker using the flexible printed voice coils. As shown in FIG. 6, the SPL frequency response curve of the loudspeaker using the frameless winding voice coils is similar to that of the flexible printed voice coils; the effective frequency domain of the SPL frequency response curve of the loudspeaker using the frameless winding voice coils is wide (180-20 KHz), and the SPL curve is smooth.

According to the vibration system of the loudspeaker provided by this embodiment, the frameless winding voice coils are directly adhered on the diaphragm, and the enamelled wires are arranged by being located in a tightly packed arrangement and in contact with each other, so that a space utilization rate in the magnetic gap is effectively improved and the driving force factor is improved. Meanwhile, a bobbin for winding the voice coils is unnecessary, and a plane, that is the upper or lower surface of the voice coil, of each winding voice coil can be directly adhered on the diaphragm, so that the unnecessary weight is reduced. The reduction in thickness of the full-range loudspeaker is further ensured, and an output sensitivity of the loudspeaker is improved.

The loudspeaker including the above-mentioned vibration system has uniform stress applied on the diaphragm, has good power tolerance and heat dissipation properties, and can be widely applied to a thin electronic device The above disclosure is merely exemplary and provides explanations for the structure of the invention, and the description is specific and detailed but cannot be understood as a limit to the patent scope of the invention thereto. It is to be noted that those of ordinary skill in the art may further make a plurality of variations and improvements without departing from the concept of the invention and these obvious replacement forms all pertain to the protection scope of the invention which is defined by the claims.

Claims

What is claimed is: 1 A vibration system for a loudspeaker, comprising a diaphragm (1) and frameless winding voice coils (2) directly adhered on the diaphragm (1), wherein each frameless winding voice coil (2) is a planar coil formed by winding a single enamelled wire, and the enamelled wires are arranged in a tight-packed manner so that adjacent enamelled wires are in contact with each other.
2. The vibration system according to claim 1, wherein each planar coil is in a shape of a racetrack or has an annular form.
3 The vibration system according to claim 1 or claim 2, wherein when two or more of the frameless winding voice coils are used simultaneously, the two or more of the frameless winding voice coils are connected to each other in a series electrical connection or parallel electrical connection, 4 The vibration system according to claim 3, wherein when the two or more of the frameless winding voice coils are used simultaneously, the two or more of the frameless winding voice coils are arranged in the same plane and in parallel, or arranged by overlapping one coil over the other..The vibration system according to any of the previous claims, wherein the enamelled wire of each frameless winding voice coil has a thickness in a range from 0.05mm to 0.5mm and a width in a range from 0.05mm to 0.5mm.6 The vibration system according to any of the previous claims, wherein the enamelled wire of each frameless winding voice coil is a flat wire, a square wire, a rectangular cross-section wire or a rounded wire 7 The vibration system according to any of the previous claims, wherein each enamelled wire is a copper wire, an aluminium wire or a copper-clad aluminium wire.8. A loudspeaker comprising the vibration system according to any one of claims 1 to 7.